2019 Reprint of 1923 Edition. Scepticism and Animal Faith marks an important departure from his Santayana's philosophy and serves as "a critical introduction" to and résumé of his new system developed in the four-volume Realms of Being (1928, 1930, 1937, 1940), an ontological (nature of being) treatise of great concentration and finish. In these later works Santayana enhanced his stature as a philosopher by achieving greater theoretical precision, depth, and coherence. Scepticism and Animal Faith conveys better than any other volume the essential import of his philosophy. It formulates his theory of immediately apprehended essences and describes the role played by "animal faith" in various forms of knowledge. Contents There is no first principle of criticism -- Dogma and doubt -- Wayward scepticism -- Doubts about self-consciousness -- Doubts about change -- Ultimate scepticism -- Nothing given exists -- Some authorities for this conclusion -- The discovery of essence -- Some uses of this discovery -- The watershed of criticism -- Identity and duration attributed to essences -- Belief in demonstration -- Essence and intuition -- Belief in experience -- Belief in the self -- The cognitive claims of memory -- Knowledge is faith mediated by symbols -- Belief in substance -- On some objections to belief in substance -- Sublimations of animal faith -- Belief in nature -- Evidences of animation in nature -- Literary psychology -- The implied being of truth -- Discernment of spirit -- Comparison with other criticisms of knowledge.